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https://bugs.gentoo.org/890286
https://github.com/mchehab/rasdaemon/issues/77
https://github.com/mchehab/rasdaemon/commit/6f7851f72d8464c7a20a248d4abf4362de8f0ba9
From 6f7851f72d8464c7a20a248d4abf4362de8f0ba9 Mon Sep 17 00:00:00 2001
From: Shiju Jose <shiju.jose@huawei.com>
Date: Sun, 5 Mar 2023 23:14:42 +0000
Subject: [PATCH] rasdaemon: fix table create if some cpus are offline
Fix for regression in ras_mc_create_table() if some cpus are offline
at the system start
Issue:
Regression in the ras_mc_create_table() if some of the cpus are offline
at the system start when run the rasdaemon.
This issue is reproducible in ras_mc_create_table() with decode and
record non-standard events and reproducible sometimes with
ras_mc_create_table() for the standard events.
Also in the multi thread way, there is memory leak in ras_mc_event_opendb()
as struct sqlite3_priv *priv and sqlite3 *db allocated/initialized per
thread, but stored in the common struct ras_events ras in pthread data,
which is shared across the threads.
Reason:
when the system starts with some of the cpus offline and then run
the rasdaemon, read_ras_event_all_cpus() exit with error and switch to
the multi thread way. However read() in read_ras_event() return error in
threads for each of the offline CPUs and does clean up including calling
ras_mc_event_closedb().
Since the 'struct ras_events ras' passed in the pthread_data to each of the
threads is common, struct sqlite3_priv *priv and sqlite3 *db allocated/
initialized per thread and stored in the common 'struct ras_events ras',
are getting overwritten in each ras_mc_event_opendb()(which called from
pthread per cpu), result memory leak.
Also when ras_mc_event_closedb() is called in the above error case from
the threads corresponding to the offline cpus, close the sqlite3 *db and
free sqlite3_priv *priv stored in the common 'struct ras_events ras',
result regression when accessing priv->db in the ras_mc_create_table()
from another context later.
Solution:
In ras_mc_event_opendb(), allocate struct sqlite3_priv *priv,
init sqlite3 *db and create tables common for the threads with shared
'struct ras_events ras' based on a reference count and free them in the
same way.
Also protect critical code ras_mc_event_opendb() and ras_mc_event_closedb()
using mutex in the multi thread case from any regression caused by the
thread pre-emption.
Reported-by: Lei Feng <fenglei47@h-partners.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
---
ras-events.c | 16 +++++++++++++++-
ras-events.h | 4 +++-
ras-record.c | 12 ++++++++++++
3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/ras-events.c b/ras-events.c
index 49e4f9a..5fe8e19 100644
--- a/ras-events.c
+++ b/ras-events.c
@@ -625,19 +625,25 @@ static void *handle_ras_events_cpu(void *priv)
log(TERM, LOG_INFO, "Listening to events on cpu %d\n", pdata->cpu);
if (pdata->ras->record_events) {
+ pthread_mutex_lock(&pdata->ras->db_lock);
if (ras_mc_event_opendb(pdata->cpu, pdata->ras)) {
+ pthread_mutex_unlock(&pdata->ras->db_lock);
log(TERM, LOG_ERR, "Can't open database\n");
close(fd);
kbuffer_free(kbuf);
free(page);
return 0;
}
+ pthread_mutex_unlock(&pdata->ras->db_lock);
}
read_ras_event(fd, pdata, kbuf, page);
- if (pdata->ras->record_events)
+ if (pdata->ras->record_events) {
+ pthread_mutex_lock(&pdata->ras->db_lock);
ras_mc_event_closedb(pdata->cpu, pdata->ras);
+ pthread_mutex_unlock(&pdata->ras->db_lock);
+ }
close(fd);
kbuffer_free(kbuf);
@@ -993,6 +999,11 @@ int handle_ras_events(int record_events)
/* Poll doesn't work on this kernel. Fallback to pthread way */
if (rc == -255) {
+ if (pthread_mutex_init(&ras->db_lock, NULL) != 0) {
+ log(SYSLOG, LOG_INFO, "sqlite db lock init has failed\n");
+ goto err;
+ }
+
log(SYSLOG, LOG_INFO,
"Opening one thread per cpu (%d threads)\n", cpus);
for (i = 0; i < cpus; i++) {
@@ -1005,6 +1016,8 @@ int handle_ras_events(int record_events)
i);
while (--i)
pthread_cancel(data[i].thread);
+
+ pthread_mutex_destroy(&ras->db_lock);
goto err;
}
}
@@ -1012,6 +1025,7 @@ int handle_ras_events(int record_events)
/* Wait for all threads to complete */
for (i = 0; i < cpus; i++)
pthread_join(data[i].thread, NULL);
+ pthread_mutex_destroy(&ras->db_lock);
}
log(SYSLOG, LOG_INFO, "Huh! something got wrong. Aborting.\n");
diff --git a/ras-events.h b/ras-events.h
index 6c9f507..649b0c0 100644
--- a/ras-events.h
+++ b/ras-events.h
@@ -56,7 +56,9 @@ struct ras_events {
time_t uptime_diff;
/* For ras-record */
- void *db_priv;
+ void *db_priv;
+ int db_ref_count;
+ pthread_mutex_t db_lock;
/* For the mce handler */
struct mce_priv *mce_priv;
diff --git a/ras-record.c b/ras-record.c
index a367939..adc97a4 100644
--- a/ras-record.c
+++ b/ras-record.c
@@ -763,6 +763,10 @@ int ras_mc_event_opendb(unsigned cpu, struct ras_events *ras)
printf("Calling %s()\n", __FUNCTION__);
+ ras->db_ref_count++;
+ if (ras->db_ref_count > 1)
+ return 0;
+
ras->db_priv = NULL;
priv = calloc(1, sizeof(*priv));
@@ -912,6 +916,13 @@ int ras_mc_event_closedb(unsigned int cpu, struct ras_events *ras)
printf("Calling %s()\n", __func__);
+ if (ras->db_ref_count > 0)
+ ras->db_ref_count--;
+ else
+ return -1;
+ if (ras->db_ref_count > 0)
+ return 0;
+
if (!priv)
return -1;
@@ -1018,6 +1029,7 @@ int ras_mc_event_closedb(unsigned int cpu, struct ras_events *ras)
log(TERM, LOG_ERR,
"cpu %u: Failed to shutdown sqlite: error = %d\n", cpu, rc);
free(priv);
+ ras->db_priv = NULL;
return 0;
}
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